Light Flicker

[EddieB]

All
Just replaced a Consumer unit new tails etc etc, when the electric shower kicks in it causes the lights to flicker.The shower is 9kw and is run in 6mm distance of about 8m. I have checked for loose connections. I'm going to load test with a clamp meter but I'm not expecting anything out of the ordinary. Any ideas anyone?

 

[nickblake]

you will get a flicker on the lights when that sort of load is suddenly switched on ,having said that this could be a problem with a neutral at the icomming supply do a Ze test and see what the readings are any higher than youd expect call out the DNO as prevention is better than cure !! oh just a though check the bus bar connections on the mcb's its possible the bus bar has missed the clamp on the MCB

 

[Jimmy Boy]

Depending on reference method isn't that 6mm close to over the rated CCC for a 9KW ?

 

[Newsome3]

wouldnt you be etter with 10mm for 9kw shower??

 

[ringer]

Don't see how cable size would affect the stated problem which is flickering lights.
What is the duration of the lights flickering? Are they flickering all the time the shower is on, or just when it is switched on?

 

[IQ Electrical]

Don't see how cable size would affect the stated problem which is flickering lights.
What is the duration of the lights flickering? Are they flickering all the time the shower is on, or just when it is switched on?

Yes, this is the key question, a flicker on start/stop is normal 'inrush', a constant flickering would probably indicate a loose connection arcing under the increased load.

I had this on a call-out only a few weeks ago and it turned out to be on the line terminal on the meter!

 

[EddieB]

Hi all
Cable size isn't an issue, connections all seem ok, I'll have a look at the incoming supply termination tightness etc, the Flicker is only for the initial switch on, but i have the same set up at my place and no flicker there.

 

[malcolmsanford]

If it's a dual board are they both on the same RCD ? If they are try just swopping over to different devices, shouldn't make a difference, but stranger things have happened.